Sander and control therefor



Sept. 27, 1938- E. JOHNSON ET AL SANDER AND CONTROL THEREFOR 2 Sheets-Sheet 1 Filed June 16, 1937 C. P. CADY v LYNN E. U'oHNsoN conditions where the road is wet or icy. A more Patented Sept. 27, 1938 SANDER, AND CONTROL THEREFOR Lynn E. Johnson and Charles P. Cady, Canastota, N. Y., assignors to Westlake Manufactur ing Corporation, Canastota, N. Y., a corporation of New York Application June 16, 1937, Serial No. 148,568

12 Claims. (Cl. 291-224) This invention appertains to sanding appliances for motor vehicles and the like, and more particularly, to an improved sand control valve and instrumentalities for actuating the same whereby to regulate and control the discharge of sand or other equivalent material'in the paths of the vehicle wheels for the purpose of preventing skidding and for improving traction under in side elevation, of a conventional motor vehicle chassis, including the usual internal combustion engine mounted thereon and which serves to propel the vehicle, and particularly illustrating our improved sander appliances and associated controls;

Figure 2 is a top plan view of the apparatus illustrated in Figure 1;

Figure 3 is an enlarged fragmentary view, in end elevation, of one of our improved sander apcomplete understanding of the general system of sand distribution may be had from reference to our copending application Serial No. 63,413, filed February 11, 1936.

One of the primary objects of the invention is to provide an improved type of sand control valve which is considerably more efficient and practical than the valve disclosed in the application above referred to. In this connection, our improved valve structure is more reliable in operation and is less likely to stick or become jammed due to the collection of sand intermediate the valve body and its seat. Obviously, reliability of operation is an important desideratum in apparatus which is intended for use under emergency conditions.

Another object of the invention is to provide a control for the sand valve above referred to, which is more simple in construction and otherwise an improvement over the control mechanism disclosed in our copending application. More particularly, our improved sand valve control is preferably of the fluid operated type, involving preferably a vacuum responsive element which is operable by the vacuum created in the intake manifold of the internal combustion engine by which the vehicle, on which the sanding apparatus is mounted, is driven.

A still further object of the invention is to provide means for insulating the sand distributing instrumentalities which form a part of the sanding apparatus, and more particularly, to provide a dead air chamber around the sand distributing instrumentalities which serves not only to reduce heat loss and thereby insure a free flow of the sand through the apparatus, but also serves as a housing for protecting the parts of the sand valve control mechanism which would otherwise be exposed to the weather and accumulations of dirt, snow, ice, etc., which would have a tendency to interfere with the operation of these instrumentalities.

Other and further objects and advantages of the invention will be hereinafter described, and the novel features thereof defined by the appended claims.

In the drawings:

and shown in section, and the end cover of the dead air chamber removed to disclose certain of the sand valve control instrumentalities which form a part thereof;

Figure 4 is a. vertical sectional view, taken approximately on the line 4-4 of Figure 3; and

Figure 5 is a horizontal sectional view, taken through the sand control valve instrumentalities on a plane generally indicated by the line 5-5 of Figure 4.

Like reference characters designate corresponding parts in the several figures of the drawings.

In Figures 1 and 2, I designates generally the frame of a motor vehicle which may be of any suitable type, such as a pleasure vehicle, passenger bus, truck, or the like, having the usual rear driving wheels 2 and the front steering wheels 3. The engine or motor, which in this instance is of the internal combustion engine type, is designated 4, and includes an exhaust manifold v5 and an intake manifold 15. Mounted on the are a plurality of sanding devices generally designated I. As shown, these sanding devices are disposed in advance of the driving or traction wheels, which, in this instance, are the wheels 2.

ing devices as there are wheels, but ordinarily'a pair of sanding devices, one for each of the rear wheels 2, is suflicient.

Each .of the sanding devices includes a sand vehicle frame or the vehicle body (not shown),

Of course, if desired, there may be as "many sandhopper or receptacle 8, to the lower end of which I.

Figure 1 is a more or less diagrammatic view,

pliances, certain of the parts being broken away signed primarily for use where a separate heater affording a source of hot air is available for forced circulation through the unit by means of a motor driven impeller, but in the present application, the sand distributing unit is shown in its adaptation to a truck or similar vehicle where no separate heater is provided, and accordingly,

the construction of the sander and installation is thereby simplified. In other words, the sand distributing unit or body, as disclosed in the former application, may be adapted to the simplified sanding system of the present application by a very simple and slight modification of the intercommunicating chambers and passages therein, as will become apparent as the description herein proceeds.

Referring to Figures 3 and 4, the body of the distributing member 9 is provided with a vertically disposed continuous sand passage H] extending therethrough from top to bottom, and at one side of this passage ID is a second passage II, which is closed at its upper end and open at its lower end at about the same plane as the lower end of the passage ID. This passage II is adapted to communicate with the exhaust pipe I2 which leads from the exhaust manifold 5, and to this end, there is provided a plate I2, carrying a coupling |3, which is secured to the body of the sand distributing member 9, as by screws M, in substitution for the motor driven impeller unit disclosed in the previous application. The exhaust pipe I2 is connected to the coupling I3 of each of the sanding devices by means of conduits I5, and it will be noted that the connection of these conduits I5 is made with the exhaust pipe |2 intermediate the manifold 5 and muffler l6. Thus, the back pressure created by the mufiier IS in the exhaust pipe l2 causes part of the exhaust gases to pass from the exhaust pipe |2 into the conduits 5, and thence into the passages of each of the sander devices, and the heat of the exhaust gases is utilized to keep the sand and the parts of the sanding device, particularly the sand distributing body 8, dry, thereby insuring a free flow of the sand through the sand pasage Iii.

In adapting the sand distributing body or unit 9 of our former application to this type of system, the intermediate chamber formerly provided, and into which the hot air was formerly directed through the intake opening or openings I8, and thence through port l9 into the passage ll, according to the former system, may be omitted entirely. On the other hand, by blocking the port l9 by means of a plug or cover plate 2|], the old distributing body may be used in the present system without change from its former construction. The plug or plate thus prevents the exhaust gases from escaping from the passage into the chamber I7 and out through the ports or openings l8, and causes all of the hot gases which enter the passage II to flow out through the lower open end of this passage I.

Secured to the lower end of the distributing body 9, is a nozzle 2|, which may be generally similar to the nozzle disclosed in our prior application previously referred to. This nozzle is disposed with its outlet opening 22 facing the traction wheels 2, and serves to direct and spread the sand in the path of the traction wheels 2, responsive to the flow of sand through the sand passage l0 and the force of the exhaust gases flowing through the passage II. It is important to note that the exhaust gases are maintained separate from the sand, preferably until after the sand enters the nozzle 2|, and that the nozzle is provided with a downwardly and rearwardly inclined wall 23 which directs the exhaust gases into intimate contact with the sand as it is discharged from the lower end of the sand passage l0 into the nozzle. The nozzle is preferably constructed so as to be readily removed from the distributor unit for replacement by a nozzle of different size or shape, according to the conditions of use, and by selecting the proper nozzle, the deflecting angle and spread of the sand to the desired width in the path of the traction wheels may be controlled as desired.

To reduce the heat loss or radiation of the heat in the distributing unit, which is derived from the hot exhaust gases flowing through the passage H, we preferably encase the distributing unit 9 in a casing or housing 24. This housing is preferably composed of sheet metal, and one end 25 is preferably removable to afford access to the interior of the housing. The removable section is flanged, as at 26, and this flange fits snugly within the open end of the housing which is to be closed by this cover 25. Suitable fastening devices such as screws (not shown) may be provided to removably secure the cover 25 in place.

Mounted on the upper end of the distributing member 9, and extending upwardly into the sand hopper or reservoir 8, is a block 21, which is provided with a passage 28 registering with the sand passage l0 and constituting an upwardly extending continuation of the sand passage. This block 2'! constitutes a valve seat, and is provided on its upper face with trough-like recesses 29 and 30 extending at opposite sides of the passage 28. These recesses 29 and 30 are downwardly inclined from their respective ends towards the passage 28, so as to direct any sand which may happen to collect therein, into the passage 28 In other words, the valve seat 21 may be said to be self-draining or self-cleaning. 3| generally designates the sand valve body which is mounted upon the upper end of the valve seat 21 for rotary movement horizontally. The valve body 3| is fixedly secured to a stem 32 which extends downwardly through the seat 21 to a point below the upper end of the sand distributing member 9, thereby disposing the lower extremity of the stem within the casing or housing 24. The stem is free to turn in the valve seat 21 which acts as a bearing for the stem. The valve body 3| may be said to be generally wedge-shaped in horizontal cross-section, and is provided with an arcuate, vertically disposed face 33 at its outer end. A recess 34 is provided in the valve body, as best seen in Figure 5, which divides the body into spaced sections 35 and 3B. The recess 34 extends from top to bottom of the valve body 3| and radia ally inwardly from the outer arcuate face 33 thereof sufficiently far to, completely uncover the upper end of the passage 28 in the valve seat when the valve body is rotated to the broken line posi-= tion illustrated in Figure 5. Seated on the block or valve seat 21 and secured thereto by means of the bolts 31 and 3B, is a casing or housing 39 which encloses the valve 3|, and the wall 40 of which is arcuate to correspond with the arcuate face 33 of the valve. This wall 40 is provided with a port 4| which constitutes the'entrance for the sand in the sand hopper 8, in its passage to the sand distributing member. Now when the valve 3| is rotated to the full line position illustrated in Figure 5, the port 4| is closed by the section 35 of the valve body which lies at sand from entering the port 4|. When the valve is rotated in the opposite direction to the broken line position illustrated in Figure 5, the recess 34 registers with both the port 4| and the passage 28 so that the sand in the hopper 8 may flow by gravity through the port 4| in the wall 49 of the valve casing 39, and thence through the passage 28 in the valve seat 21, and on through the sand passage H1 in the distributing member 9, from which it is ultimately discharged into the nozzle 2|.

It is important to note that the port 4| and the valve 3| are disposed substantially above the bottom of the sand hopper 8. This prevents the entrance of moisture or water into the sand tube or passages, bearing in mind that it is not always possible to keep water from collecting in the sand hopper, due to condensation, severe weather conditions, or the like. If snow or water should get into the hopper 8, it will collect at the extreme lower end of the hopper, below the port 4|, and it can be removed or drained, when occasion requires, by thesimple expedient of removing the nuts 42 and 43 which serve to secure the distributing member 9 to the bottom of the hopper 8, and lowering the distributing member away from the hopper to permit the hopper to be cleaned out. Moreover, the edge of the valve seat or block 21, near the port 4|, is rounded downwardly, as at 44, to prevent the collection of moisture thereon, which otherwise might freeze and interfere with the operation of the sand valve 3| after a period of idleness where the vehicle has been allowed to stand idle during cold weather. Of course, whenever the vehicle is in operation, the heat of the exhaust gases is transmitted not only to the distributing member, but also to the valve seat 21, the valve 3|, and associated parts, keeping all of these parts continuously warm, and aiding to maintain the sand in the hopper 8 in a dry condition so that it will flow freely from the hopper whenever the sand valve is operated to admit sand into the sand passage of the distributing member. Moreover, the dead air space within the housing 24 minimizes heat loss through radiation, and generally improves'the eificiency of the system.

According to our present invention, the sand valve 3| is actuated preferably by fluid responsive means. More particularly, the fluid responsive means includes a diaphragm unit, generally designated 45, which is adapted to be connected to the intake manifold 6 of the vehicle motor 4. This diaphragm unit 45 may be of conventional construction, and generally includes a two-part housing 45 within which is mounted a flexible diaphragm 4'! having its marginal edge secured intermediate the two parts of the housing 46. The housing 46 defines a chamber at each side of the flexible diaphragm 41, and the diaphragm 41 is free to flex in opposite directions, as will be best understood from reference to Figure 3. One side of the housing 46 is connected, as at 48, to a conduit 49, which leads to a three-way valve, designated 56. This valve 58 is preferably mounted on the vehicle dash 5|, or at some point conveniently accessible to the operator ofthe vehicle, and is provided with a manual control, generally designated 52, for operating the valve. The valve in turn is connected by a conduit 53 tothe intake manifold 6, and a vacuum tank or reservoir 54 is preferably interposed between the 3' valve 56 and the manifold so as to maintain a constant vacuum supply. 55 designates more or less diagrammatically a check valve interposed between the vacuum tank 54 and the manifold 6 so as to maintain the vacuum in the tank 54, irrespective of fluctuations in pressure created in the intake manifold 6 responsive to fluctuations in the power demand on the vehicle motor 4.

The valve control instrumentalities illustrated in Figure 1 represent the position which cuts off the source of vacuum from the line 49. In other words, the line 49 is normally relieved and is in communication with the atmosphere by reason of the well known arrangement of the ports in a conventional three-way valve, one of which ports communicates with the atmosphere, as generally indicated at 56. By pulling the valve control instrumentalities 52 in a rearward direction to rotate the control valve 50 in a corresponding direction, the relief port 56 is closed, and communication is established between the line 49 and the vacuum tank 54, as will be obvious. Under such a condition, the chamber 51 in the casing 46 will be evacuated, thereby causing the flexible diaphragm 41 to move to the right, as viewed in Figure 3, and this flexed position of the diaphragm will be maintained so long as the righthand side of the diaphragm is subjected to the vacuum action.

The diaphragm 4'! is interconnected with the valve stem 32 of the sand valve 3|, by means of a connecting rod 58, one end of which is secured as at 59, to the diaphragm, and the opposite end of which is pivotally secured, as at 60, to one arm 6| of a bell-crank lever generally designated 62, which in turn is fixedly mounted on the lower extremity of the valve stem 32. A set screw 63 permits adjustment of the connection between the connecting rod 58 and the arm 6|, as will be obvious from reference to Figures 3 and 4. The bell-crank lever 62 is also preferably provided with another arm 64, which is adapted toabut against the body of the sand distributing member 9 tolimit the rotation of the valve stem 32 in one direction. 4

Interposed between the lever 62 and the laterally extended flange 65 formed on the upper end of the body of the distributing member 9, is a coil spring 66, which serves to yieldably urge the rotary sand valve 3| downwardly into firm engagement with the upper face of the block or seat 27, thereby minimizing the likelihood of sand getting under the sand Valve and interfering with the operation of the Valve. This spring 66 may be similar to that disclosed in our prior applica-L tion, whereby to normally urge the valve stem 32 in one direction of its rotation, which is to, say, to a position closing the port 4|, and preventing the sand from passing from the sand hopper 8 to the sand passages 28 and H). To this end, one end 61 of the spring 66 is extended and abuts against the face of the distributing member 9, while the opposite end of the spring 66 is extended, as at 68, and engaged behind the arm 6| of the bell-crank lever 62. The force of this spring is suficient to overcome the friction between the rotary valve 3| and its seat so as to always insure that the valve will return to its closed position after operation and. release of the operating instrumentalities. Instead of availing of the spring 66 to normally restore the valve 3| to closed position, as just described, the spring 66 may have the form of a purely compression spring so that its axial expansion merely tends to hold the valve 3| firmly against its seat. In such a case, a second compression spring 69, surrounding the connecting rod 58, and interposed between the swivel l9 and the side of the housing 24 may be availed of to normally urge the sand valve 3| to closed position, as will be obvious from reference to Figure 3. On the other hand, both springs may be used as shown in the drawings, in which event, spring 69 supplements the action of the spring 66 in returning the sand valve 3| to closed position.

The vacuum responsive element or unit 45, which actuates the sand valve 3|, is preferably mounted on the side wall of the housing 24, and to this end, is provided with a threaded sleeve 1 I which extends through an opening in this wall so as to project interiorly of the housing 24. A clamping nut 12 is threaded onto this sleeve 1| and. clamps the unit 45 securely against the side wall of the housing. Inasmuch as the housing 24 is preferably made of relatively light gauge sheet metal, there would be a tendency for the wall on which the unit 45 is mounted to bend outwardly due to the pull of the vacuum exerted on the flexible diaphragm 41 which serves to actuate the sand valve 3| to open the port 4| against the yieldable force of the springs 66 and To stiffen this side wall and prevent its flexing as just described, there is provided a plate 13 which is secured to the inner face of the housing wall as by clamping the plate between the nut 12 and the wall, adjacent to the removable end of the housing. The edge of this plate which faces the removable cover 25 is offset laterally, as at 74, thereby forming a channel into which the flange 26 of the cover 25 is adapted to be interlockingly received. Thus when the vacuum acts upon the diaphragm 4! to pull the diaphragm and interconnected parts to the right, as illustrated in Figure 3, the wall of the housing upon which the unit is mounted is prevented from flexing outwardly due to the interlocking engagement of the plate 13 with the flange 26 of the cover 25. The flange 26, which preferably extends all the way around the margin of the cover 25, acts as an abutment for preventing this same wall and the outer walls from flexing inwardly when forces are applied thereto in a direction tending tocollapse the walls inwardly, and the wall on which the element 45 is mounted is reinforced against flexing both outwardly as well as inwardly.

Summarizing the operation of the sanding appliances, which, it will be noted, are mounted at opposite sides of the vehicle, as shown in Figures 1 and 2, a portion of the exhaust gases is diverted from the exhaust pipe l2, which is connected with the exhaust manifold 5, through the conduits l5 and into the passage ll of each of the sand distributing bodies 9 at opposite sides of the vehicle, thereby heating the bodies and thus tending to keep the sand passages I9 dry. The heat which is imparted to the sand distributing bodies is conducted through the metal parts to the sand valve parts which are disposed in the lower ends of the sand hoppers 8, thereby tending to keep the sand in the hoppers dry also, as well as the adjacent movable parts of the instrumentalities which control the flow of the sand. The dead air chambers formed by the housings 24 around the respective sand distributing bodies 9 trap a part of the heat and material- 'ly reduce the heat loss by radiation, and by reahousings. The exhaust gases pass downwardly through the passages II to the nozzles 2| at the.

lower ends of the distributing bodies 9, and thence rearwardly outwardly through the discharge openings 24 of the nozzles.

Now when it is desired to distribute sand over the traction surface and into the paths of the traction wheels 2, the vehicle operator pulls the knob 52 rearwardly, thereby actuating the threeway valve to a position establishing communication between the lines 49 and the vacuum tank 54. The vacuum acts upon the flexible diaphragms 41 to pull the diaphragms outwardly within their casings 46, thus rotating the sand valve stems 32 in a direction to uncover the ports 4| in their respective walls 46 of the valve housings or casings 39. This open position of the sand valves 3| is illustrated in broken lines in Figure 5. When the valves 3| are actuated to the open positions just referred to, the sand in the hoppers 8 is allowed to enter the ports 4|, by gravity, and thence the sand drops through the vertical passages 28 in the valve seats 21, and continues downwardly through the passages ID in the distributing bodies 9. The sand then enters the nozzles 2| and drops into the path of the exhaust gases, which gases flow continuously through the nozzles, and the sand becomes entrained with the gases and is directed thereby through the discharge openings 22 of the nozzles which serve to spread the sand over the desired area of the traction surface or roadway.

It is important to note that the sand valves 3| are so constructed and arranged that the weight of the sand in the sand hoppers 8 is not imparted to the valves, and thus cannot interfere materially with the actuation of the sand valves. This is a distinct improvement over our former construction, and affords a sand control valve mechanism which is easier to operate. In other words, less force is required to actuate the sand control valves, and there is considerably less likelihood of the valves sticking or becoming jammed, according to our present construction, either due to the weightof the sand in the hoppers 8, or due to ice formations during an idle period when the vehicle is not in use.

To discontinue discharge of the sand, the manually operable instrumentalities 52 are restored to the position illustrated in Figures 1 and 2, thereby actuating the three-way valve 50 to a position cutting off communication of the lines '49 with the vacuum tank 54 and establishing communication of these lines 49 with the atmosphere through the relief port 56. The flexible diaphragms 41 thus will automatically assume a flexed position in the opposite direction, as illustrated in Figure 3, and the sand valves 3| will automatically be restored to their normal positions closing the ports 4|, as shown in full lines in Figure 5, responsive to the urge of the springs 66 and 69. Subsequent discharges of sand can be attained by manually actuating the control instrumentalities 52 when desired, as

- previously described, and during the periods when the sand is not being discharged, the exhaust gases continue to pass through the passages II and out through the nozzles 2|, thereby keeping the parts of the sander appliances and the sand in the hoppers 8, warm and dry, which insures that the sand will flow freely whenever it is desired to spread sand on the traction surface. By reason of the closing or blocking of the openings |9 within the sand distributing bodies 9, by means of the closures 20, water, dirt, etc. is prevented from getting into the chambers which are formed by the housings 24 and cannot interfere with the free operation of the instrumentalities which connect thefiexible diaphragms 41 with the valve stems 32. This is =an'important feature when our old type of distributing body is 'used in the system disclosed herein, because if shown and described,the invention is not con fined thereto, as changes and alterations may be made without departing from the spirit thereof as defined by the appended claims.

Having thus described our invention," whatwe claim as new and desire to secure by Letters Patent is. L

1. In a sander of the class described,including a receptacle adapted to contain sand or the like;

and a sand distributing member depending below said receptacle and having a passage extending therethrough for directing the sand from the receptacle to the desired point on a traction surface, valve means for controlling the flow of sand through the distributing member, a housing surrounding said distributing member in spaced relation thereto to form a dead'air space, pressure responsive means mounted on said housing for actuating said valve means, said pressure responsive means including a flexible diaphragm, means substantially disposed within the housing for interconnecting said diaphragm and said valve means, and means for creating a vacuum at one side of said diaphragm.

2. In a sanding device of the class described, including a receptacle adapted to contain sand or the like, a sand distributing member depending below said receptacle and having a passage extending therethrough for directing the sand from the receptacle to the desired point on a traction surface, said distributing member also having means adapted to communicate with the exhaust of a motor vehicle or the like for heating the distributing member, and a nozzle mounted on the lower end of the distributing member for spreading the sand as it is discharged from the distributing member, a sheet metal housing surrounding the distributing member with its side Walls disposed in spaced relation thereto, whereby to form a dead air space, valve means associated with the sand passage for controlling the flow of sand therethrough, pressure responsive means including a flexible diaphragm mounted on a wall of the housing aforesaid'and interconnected with the valve means, said pressure responsive means being adapted to be connected to a source of vac-. uum, and means for stiffening the wall of the housing on which the pressure responsive means is mounted whereby to prevent flexing of the wall when the pressure responsive means is actuated, and said housing substantially enclosing both the distributing member and the means interconnecting the diaphragm and valve means.

3. In a sanding device of the class described, including a receptacle adapted to contain sand or the like, and a sand distributing member depending below said receptacle and having a passage extending therethrough for directing the sand from the receptacle to the desired point on a traction surface, valve means disposed within said receptacle and spaced above the bottom thereof, for controlling the flow of sand through said sand passage, a valve seat having a sand passage therethrough interposed between 1 the valve and the upper end of the sandpassagerof the distributing member, said valve means comprising a rotary valve body having, its axis of rotation'disposed substantially vertically,,the outer extremity of isaid'body which isremotefrom the axis of rotation being disposed substantially vertically and'extended 'arcuately about the axis of I rotation and providedrwitha recess therein'which is shiftable into and out of register with the sand passage in the valveseat and the'distributing memberresponsive to rotation of'the valve body, and a housing enclosing the valve. body, said housing including a'vertic'allydisposed wall arouately extended corresponding to the arcuate face of the valve body, and having a; sand-port provided in said wall with which therecess in the valve body is adapted to register when 'said'rece'ss is registered'with the sand passages aforesaid, and means for rotating said valve body. 1:.

4. In a sanding device of the class-described,

includinga source of supply of .sand or equivalent material, and a sand distributing-member communicating with said source of supplyyand including a body having a sand passage therein through' which the sand is adapted to flow by gravity, means for normally. closing the sand passage. through the body aforesaid, said means including a solid valve body mounted above the sand passage and shiftable horizontally across the upper end of the sand passage about a vertical axis disposed at one side of the sand passage,

and a casing enclosing said valve body and provided with a sand intake port facing laterally re- 5. A device as claimed in claim 4, wherein the valve body is provided with a recess in oneedge extending from the upper side to the lower side thereof and adapted to simultaneously register, a

with the port in the valve casing and with the sand passage in the distributing member, responsive to rotation of the valve body in one direction.

6. A device as, claimed in claim 4, in combination with'a valve seat interposed between the valve body and the distributing member, said seat having a sand passage therethrough registering with the sand passage in the distributing member, and means for yieldably urging the valve body into close engagement with said seat,

while permitting rotation of said valve body'on said seat.

7. A device as. claimed in claim 4, in combination with a valve seat interposed between the valve body and the distributing member, said seat having a sand passage therethrough registering'with the sand passage in the distributing member, means for yieldably urging the valve body into close engagement with said seat, while permitting rotation of said valve body on said seat, and said valve seat being provided with recesses in its face which is engaged by the valve bod-y, and said recesses being downwardly inclined towards the opening in said seat whereby to cause said seat to be substantially selfcleaning.

8. The combination with a'motor vehicle having an internal combustion engine mounted which a vacuum is created responsive to operation of the engine, of a sanding appliance mounted on said vehicle for spreading sand in the path of said vehicle, said sanding appliance including a sand receptacle, a distributing member disposed below said receptacle and including a body having a sand passage extending therethrough and through which the sand is adapted to flow by gravity, valve means disposed within the receptacle for controlling the flow of sand through said sand passage, and a vacuum responsive element mounted exteriorly of the receptacle and distributing member so as to be out of the path of sand flow and being operable in response to the vac uum created in the intake manifold of the vehicle engine for actuating said valve means.

9. Apparatus as claimed in claim 4, wherein the valve shifting means comprises a pressure responsive instrumentality arranged transversely to the axis of rotation of the valve body.

10. Apparatus as claimed in claim 4, wherein the valve shifting means comprises a pressure responsive instrumentality including a flexible diaphragm arranged transversely to the axis of rotation of the valve body and connected thereto.

11. In a sanding device of the class described, including a receptacle adapted to contain sand or the like, a distributing member depending below said receptacle and having a passage extending therethrough for directing the sand from the receptacle to the desired point on a traction surface, and valve means for controlling the flow of sand through the distributing member, a housing surrounding said distributing member in spaced relation thereto, pressure responsive means including a flexible diaphragm mounted on the housing and connected through the housing to the valve means, and pressure means operable at will for actuating said diaphragm and consequently said valve means.

12. A device as claimed in claim 4, in combination with a valve seat interposed between the valve body and the distributing member, said seat having. a sand passage therethrough registering with the sand passage in the distributing member, means for yieldably urging the valve body into close engagement with said seat, while permitting rotation of said valve body on said seat, said last named means serving to normally urge the valve body in one direction of its rotation, and pressure responsive means adapted to be connected to a source of vacuum for rotating the valve body in the opposite direction.

LYNN E. JOHNSON. CHARLES P. CADY. 

